Tony1

Apologies, we will need Nick's expertise to answer this properly, but I'll give it try for now: The control wire I used was black, I think it was 18AWG. But no fuse is needed on that control wire. I'll see if I can get a pic of the back of the BMV712 later, showing the wires. The pic shows how I configured the BMV712, with Nicks help: I'm using the low SoC relay function to monitor the SoC, but I'm using it 'in reverse' as a high SoC monitor, as you'll see from the SoC settings. In terms of cycling the batteries in a way that will prolong their life, again there are many more people far more knowledgeable than me about this topic, but there are a few things I've picked up from the contributors here: They need regular runs down to lower SoC (ie lower than 10 or 20%). In my case I do that about once each week. Its awkward to arrange as a liveaboard because you need the batteries to be running down low during the day- you dont want a low voltage alarm at 4am. So you need to set things up so that you run them down to a low SoC, but you still have enough time to get some charge back into them before it gets too late. Its no use getting down to 5% SoC at 9pm, for example, as its too late too recharge in order to get your fridge through the night. So there are practical constraints, but the general principle seems to be that they need regular 'exercise', and they need to be pushed to their capacity limits periodically. One key thing to bear in mind is not to hold them at an extreme SoC for very long. In my case as soon as the BMV712 is synchronised to 100% I stop all the charging, and put the kettle on in order to draw some charge from them a bit quicker. Its more awkward in winter, because for example today we have a bit of solar, but we wont get much tomorrow. So today I've adjusted the SoC limit up to 90% to take advantage of what solar we have. It costs money (in diesel) to replace charge in winter, so you always have a bit of reluctance to switch off your MPPTs and let the batteries SoC go down, when there is some perfectly good solar available. In winter I do tend to cycle between 60 and 85% more often, as you have a natural tendency to want more charge in reserve in colder/darker weather, but I have to force myself to let them run down the SoC once every couple of weeks at most, as I know that will give them a longer life.

Might be worth just reiterating Mike's suggestion, of buying a 38hp engine but getting the uprated poly vee crank fitted before the install. When I looked at it, the poly vee crank kit was only about £300, but it depends how much they want to charge for the labour of swapping it in. If the bill starts climbing towards £1000, maybe the 42hp model makes more sense, as it already comes with a better alternator, and you might only have to pay for a controller when you install lithiums. And as Ian pointed out, the 38hp engine is not said to be ideally suited to for driving powerful alternators. It will do a job, and I've had 90 amps continuously from mine when running at 1300rpm, but there is that nagging doubt that I might be pushing it a bit- and that might become more of a concern if you start looking at 120 amp plus alternators. I must point out that I don't know, this is just guesswork, but the 42 hp model was designed to be capable of driving a more powerful alternator- so if its affordable, it seems the safer bet maybe?

I definitely don't want to downplay the cost element, but for me personally, there are a couple of things to bear in mind. First is that getting the installer to do the replacement of alternators means you save some money as they can resell the original one. Installing a alphapro might cost up to £600, I guess there's no way round that. But the second thing is to consider the overall costs over say 10 years. If you can replace all your daily charge in one hour of engine running (with an alternator that delivers say 130 amps continuously), then your diesel bill for charging might be one third that of the canaline 38 owner who can only charge at 40 amps, and has to run his engine for 3 hours each day. Solar obviously changes the figures greatly, so if you were planning on getting lots of panels, you might then only have to worry about engine charging in winter. In that scenario a big alternator plus controller might look a bit less attractive, if the total bill is approaching £1000 or so. I was thinking of one of these things- would that do the job? https://shop.chastheboat.co.uk/products/mv-alpha-pro-iii-charge-regulator-for-alternators-3-step-with-m-bus-aq-m45513000 But having lived with one of those low end alternators for a couple of years on my engine, I feel I have to at least point out to the OP that they do have some serious limitations when it comes to lithium batteries, and the cost of a later upgrade (including new crank etc) would be at least double the cost of getting it done as part of the new engine install deal. I guess it all boils down to how much future proofing you are up for, and how much you like having lots of electricity. I'm quite partial to a few amps myself.

Yes, Tony is correct in that my reservations about the 38hp engine alternators are only relevant to a possible future move to install lithium batteries, as I mentioned in my first post. Whether you have the 38 or the 42, you will still need a way to limit the current draw from the alternator if you install lithiums. Some people use the 'long piece of wire' technique, but as you'll know, the ideal world option is an alternator controller like the mastervolt/alphapro. If I were speccing a new engine myself, knowing that I will always have lithiums, I would insist on one of these devices being installed. In terms of choosing an alternator, I think the canaline 42 comes with a domestic alternator rated at 175 amps. However, I have their 100 amp model, and at tickover it cant put out more than 35-40 amps before its temp goes above 100 degrees. If the 175 amp model is similar, your maximum charging rate at tickover will be about 80 amps, which is decent- but you can probably do better. Ed Shiers website mentions a variety of good quality alternators he has installed, and there is Nick of this parish who has a very powerful alternator. Again, personally speaking, if I was spending 8 grand on a brand new engine, I would also consider asking them to replace the standard 175 amp alternator with a top quality model that will put out 120 amps or so on a continuous basis. In real terms the difference between the alternators on the canaline 38 and 42 is that if you are out cruising (and thus frequently at tickover), the 38hp model cant output more than 35 amps before it starts getting hot. If I rev up to 1300rpm it can safely put out maybe 48 amps, but I do feel like I'm pushing its capabilities a bit when doing that for an hour at a time- but so far so good, and it now two years in, touch wood etc. PS - Everyone seems to have a different view of how hot is too hot. Since the alternator used to run at about 50-60 degrees with the lead acids, I decided to use 100 degrees as my 'comfort limit' when charging the lithiums. When it got over that temp I deemed it to be getting hot enough to potentially start causing damage and shortening the lifespan of the thing. PPS- I'm sure the canalines are fine and I'm not having a go at them, but the beta engines dont cost much more, and they do seem to be a bit more positively regarded. Again, if I were getting a new engine I'd probably pick a beta over a canaline, if the cost difference was not too great. ETA- just rad Tony B's post above and I couldn't agree more- solar is a great investment for a liveaboard. Since roughly mid-Feb, I've only had to run my engine to charge on about one day in 5, and within another few weeks there will be no need at all to run the engine for charging- it takes a couple of years but the panels definitely pay for themselves in terms of diesel costs, servicing, engine wear etc..

In my case there were two issues really: The first thing was that the lead acids would no longer hold a decent amount of charge, so no matter what the panels threw at them, they were always down to about 50% in the late evening, and I was having to switch off the fridge at 11pm to make sure I would still have some power left in the morning, eg for a bit of diesel CH if it was chilly. On days when the solar is more marginal, lead acids batteries do not absorb the solar charge as readily as lithiums. So in mid-September, I was not ending up with as many Ah of charge in the lead acids as I would have in the lithiums. Yes in high summer its all fine, you get enough solar even for lead acids. But getting into Autumn and with more cloudy weather, the lithiums seem to perform a lot better. I dont know how it works, but they just seem to soak up every bit of solar charge like a sponge. I never got a chance to try them properly side by side, but my admittedly very unscientific impression was that over say a two hour solar charge in exactly the same conditions, I would end up with more Ah in the lithiums than I would in the lead acids.

I'm just not a lead acid person at all. My lead acids were 4 years old and could only hold about 50Ah when I moved aboard. So the solar would fill them up, but only with 50Ah. So I would use 25Ah between teatime and 11pm, and then I was going to bed with the batteries at 50%, which didn't seem ideal. As a liveaboard, the lithium batteries were a completely different thing- the solar charges them more efficiently, so on a marginal cloudy day, every scrap of solar power ends up going into them- there is no resistance to charging as there seemed to be with the lead acids. My opinion is admittedly coloured by the fact that I had poor lead acid batteries, but I will never willingly go back to using lead acids as house batteries.

The Op doesnt say if they live aboard or not, but it may be the key factor. A recreational boater will tend to spend more hours each week actually cruising than a year-round liveaboard does (and there will be exceptions, of course- this is a generalisation). So with many hours of charging being done each week, a recreational boater may not gain a huge benefit from lithium batteries, and in that case the standard beta 38 alternator setup might be fine. But if the OP is a liveaboard, and possibly cruising for fewer hours each week, they might at some point consider ways to generate charge more quickly, and without the hours of 'conditioning' charge needed to keep lead acids in good condition. So I would guess that at some stage over the next few years they may look at the idea of upgrading their batteries to lithium- and that is when the limitations of the crank and alternator setup would become an expensive thing to fix. But anyway, its something that is at least at least worth pointing out.

I would politely disagree. Anyone considering an investment of £7-8k in their boat for a brand new engine is clearly thinking in the long term, certainly at least 10 years. Surely if the hull is looked after properly, another 10 or 20 years is more than realistic as an expected lifespan? To be clear, I'm not suggesting that the OP is likely to consider lithium batteries in 20 years time, because different technologies will be available by then. But if they are a liveaboard then better batteries my be on their mind within the next 5 years. The key issue here is that I think it is worth pointing out the limitations of the charging systems that come as standard with brand new 38hp engines, because it is such a huge investment, and it can be very expensive to upgrade. I guess we all have to make out own assessments of the likelihood of the canals becoming a load of unnavigable sh*te in say 15 years time. It is certainly a genuine concern. But again I will repeat what I see as the key issue- the OP needs to be aware that if they consider lithium batteries and charging upgrades in the next few years, the 38hp beta and canaline engines will make that an expensive and difficult thing to do. That said, if the OP is not a liveaboard, I do think that would alter things a bit.

I tested both my alternators on a freezing january morning with the engine cover board removed, and a fan blowing into them, with a strong breeze across the stern, so they could not have have had more cooling help during the tests, but both of them were unable to put out even half of the rated power before they overheated. I've basically accepted their limitations, and set up a charging system that draws as much current as is safely possible at tickover. In fairness Tony I did add above that a more powerful alternator would only really be a benefit if lithium batteries were installed, but I do feel that over the next 10-20 years, a majority of boaters will install lithium as they get cheaper and better understood- so it could be relevant to the OP, in terms of future proofing the charging capabilities of a new engine. I cant argue with your knowledge of which are the best quality alternators, I would hope the OP will do some research before making a decision on that, and seek advice here. My advice would be look at the website of Ed Shiers, who has more practical knowledge of these matters than any marine electrician I've spoken to in the last 3 years. Re the tickover thing- I mention tickover because it's the worst case scenario, but it has to be covered. Whatever charging system the OP uses will have to be able to charge safely at tickover without overheating, because they will spend long periods at tickover- eg when going through locks, passing lines of moored boats, etc. I know the alternators can do more at higher rom. In fact I have an extra B2B installed that I only switch on when I am moored up and I can run the engine at a steady 1300rpm. The extra B2B can draw an additional 20 amps from the domestic alternator at 1300 rpm. But when out cruising I cant use the extra B2B, because cruising involves lots of engine tickover, and at tickover the domestic alternator will overheat if I try to draw those extra 20 amps from it. This is only an issue with lithiums as you say. With lead acids you are committed to many hours more of engine running over, say, a week- so a 50 amp alternator is as useful as a 200 amp model. But for me, the issue here for the OP is about future proofing. When I installed lithiums I found that my canaline 38 was crippled by the inability to upgrade the alternator- it needed an crank upgrade before I could install a decent alternator. With such a huge financial investment for a brand new engine install, and with lithium batteries becoming more popular, I think it is worth the OP knowing that the 38hp engines come as standard with what could turn out to be a major limitation, in terms of the alternators and belts setup.

This is just a thought, but maybe worth a mention: the 'entry-level' 38bhp engines by beta and canaline come as standard with alternators that are not capable of producing high charging currents over a long period. My domestic alternator is officially rated as 100 amps, but over an hour of charging it can only put out 35 amps at tickover revs. Any more output than that means it overheats. The consequence is that you have to run the engine for hours each day to recharge batteries. With a powerful alternator, and lithium batteries, you can do all your charging in one hour. Now admittedly you only get the benefit of a powerful alternator if you do have lithium batteries, but more boaters are buying lithium because of the lower costs and much stronger performance than lead acid, when taken over the expected 10-15 years of life. So I would give some thought to the charging capability of the alternator that is proposed to come with the new engine. If I were ordering a new engine, I would specify that they ditch the standard supplied alternator and install with a top quality model (I think Bosch and Iskra are pretty good for example), because that might be cheaper than replacing it further down the line when you go lithium, as most boaters will end up doing over the next 10-20 years.

There is armco for some of the way, and its worth mooring there in the summer as its off the main drag, so you wont be jerked around by passing boats every five minutes, as you will be on the main canal. But the Llangollen is still pretty quiet at the moment, so if you're going any time soon, then mooring next to Whixall Moss is a better bet if you have solar, as your sides face south-ish and its very open in aspect. You wont really have any need to divert to visit whixall marina, other than maybe to visit the cafe (which I havent tried), or the launderette. You'll have fuelled up in nantwich or whitchurch anyway, and you wont have used too much diesel by the time you reach whixall- at least not on the outward journey. Its only a few hundred yards long, and as a solo boater I was lazy and couldn't be arsed to do the lift bridges, so I moored on Whixall Moss and walked over the footbridge to the marina.

I really should get out more

It feels like I read headlines about some new type of battery technology every month or two, and each one makes bigger claims than the one before. I'm half expecting for the next big battery technology to be hybrid lithium-gerbil cells (as in the small mammal). But the thing is that I rarely hear about them again after the initial headline. So I just assumed it was mostly baloney and hype, and that LiFeP04 would continue as the best option for at least another decade. But not so- lithium titanate is actually a thing, as in people will be actually be selling them to actual people, some time this year. If I understand it right they seem to be at least twice the price of equivalent LiFeP04 batteries, but Bimble are claiming 30,000 cycles, which I guess means they will last almost ten times longer than LiFeP04's right? So they are still good value, as long as you intend to cruise your boat for the next millenium or so. We just need people to live a bit longer now, so we can enjoy the benefits of these immortal batteries.

I've seen in theory that lithiums can deliver very high currents, but part of me always stops and wonders....

Which reminds me, I need to get on the case and buy a small toaster as well as an electric hob. In the summer I am finding that even after recharging and heating up the water, I still switch off the MPPTs in early or mid afternoon, so there is a lot more free energy I could be using. Its not quite free, of course, because cycling more energy through the batteries will mean proportionally shortening their lifespan, but I'm hoping batteries will become significantly cheaper over the next decade anyway, and in any case I may be in a different boat and cruising on the French canals by then, since it appears I may well be eligible for Dutch citizenship 😁

With 2.4kw of solar I would guess the OP's electricity needs will be more than met for most of the year, and I'm sure he's already well aware of the seasonal issue, but it may be worth repeating for any newbies thinking about going electric for cooking. My own experience over the last 18 months with a 1.4kw solar setup has been that you have enough energy for hot water on most days between April and mid-Sept, so with 2.4kw of panels his solar hot water 'season' might well extend into October, and all the electrical equipment will be fine, although there may come a time in late Sept when the solar energy is reducing, and you have to choose between using the solar for hot water, or using it to power a cooker/washing machine etc. As we know, with all the solar setups, there is that period between say mid-Nov to mid-Feb, where the input is pretty paltry on most days. In Dec and Jan, on most days my panels yield barely enough power to keep a fridge running- let alone to replace any of the power used used over the last 24 hours- so there will be a lot of power generation needed on maybe 90-100 days of the year. But I do understand feeling a desire to remove gas from the picture- it feels like one less critical dependency, and that has an appeal at a time when gas supplies seem to be constantly at risk (e.g. a fuel boat text yesterday to say they will have a limited gas bottles on their next run). I'm sure there's a fair bit scaremongering about gas supplies, and there certainly was in late 2020, but it does seem to create a slight but nagging doubt. I've considered getting an induction hob myself, as a way to utilise the excess solar in the warmer months, and to further reduce the usage of gas. But in my case the gas is definitely staying put, because for those 100 days of the year when the solar is very low, having electric cooking just means more genny running/engine running, and I dont know how the cost figures stack up when comparing gas cooking to electric cooking (using electricity created from burning diesel fuel and a genny of some sort).

I dont think I was entirely clear above- I dont change the gas bottle automatically at 6 months- when 6 months are up I just check it. But I always have a spare available. To be fair, I got a bit paranoid about gas supplies during the lockdowns with so many of the sellers saying they weren't sure when their next supply was coming, so I do like to know when its coming due as I can plan to be close to a marina or fuel boat, and get a new spare asap. But that is me being over -cautious, no doubt about that. Re the water tank- yes I can see the bow rise a bit as the water tank empties, but to my inexperienced eyes that change in bow depth doesn't even come close to giving me a rough idea of when it'll run out. It sounds quite traditional and boaty, but a one-word entry of 'water' in my calendar gives me a 'run-dry' date that I can rely on, to within a day or two. And I do not take any chances when it comes to running out of water. I want to make sure I'm not too far from a facilities point when I'm running low, especially if there's a chance of things freezing. I used to carry a 10L container of emergency water but I didn't use it in two years, so I've stopped now. But without an emergency supply, I need to know when the water's going to run out. Re the mooring- I deliberately don't set a specific reminder date with the google calendar entry for the date of mooring, because I dont know what date I'll be leaving. I may stay for two days, or it may be 14, depending on all sorts of things. And as often as not, I wont leave on the date I originally planned anyway. So the original mooring date is usually the most helpful, and I've lost count of the number of times I've been stood there scratching my head and wondering when I arrived at a place, saying 'no, wait, I arrived on Friday, because it was the day before the football game, wasnt it? Or was it?' etc, etc. Making a quick entry just takes out the doubt and the head scratching.

I make an entry in my google calendar every time I fill the water, but it's not for the sake of having a record. I record it so that I can quickly check how many days it's been since it was last filled, and so I know when I'll need to get to a water point. Likewise with the gas bottle- it needs changing about every 6 months, so I make a calendar entry, and then I know when it will be next due. I also make an entry when I moor in a new location, for the same sort of reason- I can check exactly when 14 days are going to elapse, and I don't have to rely on my poor memory.

Thanks Ian, the 3,000 thing does make it easier to make a rough calculation. Hopefully most batteries will fall roughly into that same sort of performance? So in my case, if my batteries started out at about 400Ah capacity, and if I use a third of their capacity (133Ah) per day, in theory I can get 3,000 x 3 = 9,000 days of use from them? That appears to mean over 24 years of use- which won't happen- but they'll certainly outlast me on the boat. And even with solar hot water, they should still last for more than 10 years, by which time we'll be in antigravity hover boats anyway. Begone with your evil Morlock technology. That makes far too much sense.

I'm wondering if I can prompt a discussion about the costs vs benefits of solar hot water, via a question: Imagine two boaters install identical sets of lithium batteries, and they use identical amounts of charge each day for their 'normal' systems, apart from one thing- boater A also uses his batteries and inverter to power the immersion heater (for say 50% of the year). Lets assume purely for discussion purposes that boater A is handsome and dashing, and boater B is a grimy troglodyte. And just for discussion, lets say that in heating up his water, boater A cycles 50% more energy through his batteries each day than boater B. So over a year, boater A is making his batteries cycle through 25% more energy than boater B. But here is the burning question- will the troglodyte boater B's batteries last 25% longer than those of the handsome boater A? It's one thing for us dashing solar hot water bods to count our savings in terms of engine running and diesel costs etc, but if our batteries only last 7 years instead of 10, are we really making a saving? Asking for a (handsome) friend.

Apologies to the OP for banging on about solar again, as I know its been mentioned, but it is worth reiterating for a liveaboard. On 12 of the last 15 days I've had enough solar to run most of the electrics, and if I didnt run a fridge it would have been every single day. Today I got over 1700Wh of charge (charging at about 13.35v), so if I understand it right that means I got around 127Ah of charge, which is my full days usage in winter. It was a bright day, but not sunny all day long. And I am overlooked by trees to the north and east, so its not even the ideal spot for solar. If I'm already getting 130Ah of charge in a half decent day around mid Feb, that says to me that that its worth you rearranging the coal storage on the roof (ie pile the bags up higher), and getting some more panels installed. If you were getting that same amount of charge (charging with a genny or a B2B at say 40 amps), that's three hours of engine or genny running saved, in terms of fuel costs. And that's just one day. When we get into Spring the solar will go ballistic I never heard of a single liveaboard boater who regretted installing more panels.

My BSS is coming up in December, and the last thing I want is to get one of those jobsworth types who have a bee in their bonnet about about some particular issue. I was going to replace my mushrooms with flying saucer vents but I dont think I'll bother until after the inspection. Are there any examiners in the North west that folks would recommend as being a bit more reasonable and pragmatic?

You know what- the truth is I dont know- at least in the sense that I dont know exactly what the chargers are doing to the batteries during the float phase. I never use the float phase in reality, since I switch the chargers off at 85% SoC. I've messed around with the float phase a few times (eg in Llangollen), and my impression is that although the charger is not charging as such, it is sort of 'leaning' on the batteries, checking the voltage in case they need a bit more charge. And if the battery voltage drops a bit below the nominated float voltage, the charger seemed to kick in and start doing some limited charging. That was the 6 year old shore charger mind. I dont know how other units and MPPTs etc behave. I agree with you (from the things I've read) that the ideal treatment for lithiums is to just charge them and leave them alone, ie switch off the charger altogether. No float charge needed. Thats why I like my SoC-based charge management using the BMV712. It seems odd that such a basic principle- something that a relative newbie like me realised very early on in my usage- still isnt being built into the charging products that we are seeing come onto the market. My solution is to set the float voltage at 12.7v, and in fact I may go even lower.

I definitely agree with that. My charging voltages vary wildly, from 5 amps of solar in mid December, around 75 amps with the engine running, up to potentially 170 amps in summer with MPPTs and B2Bs all running. So it would be impossible in my case to set a voltage that could always guarantee you that you stop charging at a chosen SoC. By coincidence, I had to rely on voltage to manage charging for the ten days I spent in Llangollen, as my shore charger doesnt have an input for a remote BMS switch off, so my BMV712 couldnt be used to control it. And it was quite tricky. I tried 13.8v and found that the SoC was going well over 90% before it went into float. Then I tried 13.7v, and then it only charged to 70% before stopping. It was tricky to find a good setting with it.

What I'm trying to clarify is more for new lithium users, and its not so much about the specific charge voltage you choose (in fact I agree with your suggested values for a prolonged charge). My issue is this- I think potential new lithium users might get the idea that if they set their MPPT to bulk charge at 14.6v, then as soon as the sun appears above the horizon and a few amps trickle in, their battery voltage reading will jump to 14.6v, and it will stay there as the battery fills up, until the MPPT goes into float. But what actually happens, as you obviously know, is that the battery voltage increases very slowly. If 20 amps are coming in, for example, my battery voltage will stay under 13.3v for a long time. If I charge at 60 or 70 amps, the battery voltage will be maybe 13.4 or 13.5. I dont use voltage to manage the charging like almost everyone else does- but (to make it more pertinent to newbies) if I did use voltage, my battery voltage would creep up very slowly until it reached the bulk charge voltage value (lets say 13.8v), at which point the chargers would go into float. So my point was just to clarify that when people set a bulk charging voltage, that voltage will take time to be reached. And when it is reached, the charger will go into float. In other words, the bulk charge voltage, is an 'end point' voltage, it is not a voltage that is maintained throughout the charge. I dont think a lot of lithium newbies are clear about that.